The ANTI-HBC IgM (HBC Test) detects IgM antibodies to the Hepatitis B core antigen (anti-HBc IgM), a crucial marker for diagnosing an acute or recent Hepatitis B infection, often appearing early when other markers (like HBsAg) might be negative (the “window period“). Its presence strongly suggests an active infection (within the last 6 months), helping doctors differentiate between active, chronic, and past HBV cases, guiding treatment, and assessing contagiousness